Nope, im not ordering by the POINT column. Heres an example...
CREATE TABLE table1 ( title character varying, sorter integer, xy point
);
CREATE TABLE table2 ( title character varying, sorter integer, xy point
);
INSERT INTO table1 VALUES ('one', 1, '(1,1)');
INSERT INTO table1 VALUES ('two', 2, '(2,2)');
INSERT INTO table1 VALUES ('three', 3, '(3,3)');
INSERT INTO table2 VALUES ('four', 4, '(4,4)');
INSERT INTO table2 VALUES ('five', 5, '(5,5)');
INSERT INTO table2 VALUES ('six', 6, '(6,6)');
CREATE VIEW myview AS SELECT table1.title, table1.sorter, table1.xy FROM table1 UNION
SELECT table2.title, table2.sorter, table2.xy FROM table2;
SELECT title FROM myview ORDER BY sorter;
ERROR: could not identify an ordering operator for type point
HINT: Use an explicit ordering operator or modify the query.
In statement:
SELECT title FROM myview ORDER BY sorter
